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<head><meta charset="utf-8"><title>weekly meeting 2018-11-12 · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html">weekly meeting 2018-11-12</a></h3>

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<a name="147544526"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544526" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544526">(Nov 12 2018 at 18:59)</a>:</h4>
<p>Hello all <span class="emoji emoji-1f44b" title="wave">:wave:</span></p>



<a name="147544587"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544587" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544587">(Nov 12 2018 at 19:00)</a>:</h4>
<p>Honestly I've spent most of today slowly catching up and I wasnt' around last week, curious to hear from other folks though. I hope to get on top of reviews today. =)</p>



<a name="147544609"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544609" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544609">(Nov 12 2018 at 19:00)</a>:</h4>
<p>Dropbox document: <a href="https://paper.dropbox.com/doc/WG-Traits-Planning-Meeting--ALDA5111ZliLv5zlSgbjvDS2Ag-oDfr6ct8xx63HSAOOmIZX" target="_blank" title="https://paper.dropbox.com/doc/WG-Traits-Planning-Meeting--ALDA5111ZliLv5zlSgbjvDS2Ag-oDfr6ct8xx63HSAOOmIZX">link</a></p>



<a name="147544932"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544932" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544932">(Nov 12 2018 at 19:06)</a>:</h4>
<p>so <span class="user-mention" data-user-id="131694">@scalexm</span> you have a huge pending PR :)</p>



<a name="147544938"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544938" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544938">(Nov 12 2018 at 19:06)</a>:</h4>
<p>which I can try to review today hopefully</p>



<a name="147544943"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544943" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544943">(Nov 12 2018 at 19:06)</a>:</h4>
<p>what are the "next steps" in your view from what we have now?</p>



<a name="147544944"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544944" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544944">(Nov 12 2018 at 19:06)</a>:</h4>
<p>when it comes to chalk integration</p>



<a name="147544950"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544950" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544950">(Nov 12 2018 at 19:06)</a>:</h4>
<p>not that huge, there is a bit of code reordering</p>



<a name="147544964"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544964" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544964">(Nov 12 2018 at 19:07)</a>:</h4>
<p>next step is to implement missing unification routines</p>



<a name="147544973"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544973" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544973">(Nov 12 2018 at 19:07)</a>:</h4>
<p>which I'm working on currently</p>



<a name="147544995"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147544995" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147544995">(Nov 12 2018 at 19:08)</a>:</h4>
<p>(i'll probably split this work in two PRs)</p>



<a name="147545038"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545038" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545038">(Nov 12 2018 at 19:08)</a>:</h4>
<blockquote>
<p>next step is to implement missing unification routines</p>
</blockquote>
<p>do you mean the various chalk callback methods?</p>



<a name="147545043"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545043" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545043">(Nov 12 2018 at 19:08)</a>:</h4>
<p>yeah</p>



<a name="147545072"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545072" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545072">(Nov 12 2018 at 19:09)</a>:</h4>
<p>ok, there is an open issue on that I think</p>



<a name="147545157"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545157" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545157">(Nov 12 2018 at 19:10)</a>:</h4>
<p>ok well maybe we should take it easy this week and I can focus on reviewing then :)</p>



<a name="147545169"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545169" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545169">(Nov 12 2018 at 19:11)</a>:</h4>
<p>and we'll try to circle back next week and get more active? :)</p>



<a name="147545256"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545256" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545256">(Nov 12 2018 at 19:12)</a>:</h4>
<p>I was pretty busy last week also. I'll at least wrap up the SLG solver parts of the guide</p>



<a name="147545274"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545274" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545274">(Nov 12 2018 at 19:13)</a>:</h4>
<p>a first crack, that is</p>



<a name="147545277"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545277" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545277">(Nov 12 2018 at 19:13)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> I think with my<code>unification</code> branch (WIP right now) we're basically seeing the end of the implementation of chalk <code>Context</code> trait and al</p>



<a name="147545287"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545287" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545287">(Nov 12 2018 at 19:13)</a>:</h4>
<p>great!</p>



<a name="147545585"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545585" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545585">(Nov 12 2018 at 19:19)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> also did you see this issue I opened in chalk: <a href="https://github.com/rust-lang-nursery/chalk/issues/189" target="_blank" title="https://github.com/rust-lang-nursery/chalk/issues/189">https://github.com/rust-lang-nursery/chalk/issues/189</a></p>



<a name="147545598"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545598" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545598">(Nov 12 2018 at 19:20)</a>:</h4>
<p>of course it would be easy to hack around this in rustc (just write a "by-hand" coercion), but that's unfortunate</p>



<a name="147545599"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545599" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545599">(Nov 12 2018 at 19:20)</a>:</h4>
<p>I saw it, but I usually solve this sort of thing by having an explicit upcast</p>



<a name="147545659"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545659" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545659">(Nov 12 2018 at 19:20)</a>:</h4>
<p>in fact I think there are some existing methods of this kind already</p>



<a name="147545694"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545694" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545694">(Nov 12 2018 at 19:21)</a>:</h4>
<p>e.g., </p>
<div class="codehilite"><pre><span></span><span class="w">    </span><span class="k">fn</span> <span class="nf">sink_answer_subset</span><span class="p">(</span><span class="w"></span>
<span class="w">        </span><span class="o">&amp;</span><span class="bp">self</span><span class="p">,</span><span class="w"></span>
<span class="w">        </span><span class="n">value</span>: <span class="kp">&amp;</span><span class="nc">C</span>::<span class="n">CanonicalConstrainedSubst</span><span class="p">,</span><span class="w"></span>
<span class="w">    </span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nc">I</span>::<span class="n">CanonicalConstrainedSubst</span><span class="p">;</span><span class="w"></span>

<span class="w">    </span><span class="k">fn</span> <span class="nf">lift_delayed_literal</span><span class="p">(</span><span class="w"></span>
<span class="w">        </span><span class="o">&amp;</span><span class="bp">self</span><span class="p">,</span><span class="w"></span>
<span class="w">        </span><span class="n">value</span>: <span class="nc">DelayedLiteral</span><span class="o">&lt;</span><span class="n">I</span><span class="o">&gt;</span><span class="p">,</span><span class="w"></span>
<span class="w">    </span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nc">DelayedLiteral</span><span class="o">&lt;</span><span class="n">C</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span>
</pre></div>



<a name="147545715"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545715" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545715">(Nov 12 2018 at 19:21)</a>:</h4>
<p>we don't appear to have one for <code>ExClause</code></p>



<a name="147545726"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545726" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545726">(Nov 12 2018 at 19:21)</a>:</h4>
<p>mmh I guess <code>lift</code> is for going from <code>'tcx</code> to <code>'gcx</code>, no?</p>



<a name="147545729"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545729" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545729">(Nov 12 2018 at 19:21)</a>:</h4>
<p>yes</p>



<a name="147545731"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545731" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545731">(Nov 12 2018 at 19:21)</a>:</h4>
<p>but anyway we can write that by hand indeed</p>



<a name="147545732"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545732" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545732">(Nov 12 2018 at 19:21)</a>:</h4>
<p>I don't think there's another option really</p>



<a name="147545779"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545779" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545779">(Nov 12 2018 at 19:22)</a>:</h4>
<p>unless we change <code>ExClause</code> to not be parameterized by <code>C</code></p>



<a name="147545781"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545781" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545781">(Nov 12 2018 at 19:22)</a>:</h4>
<p>but rather by all the things it <em>projects out</em> from <code>C</code></p>



<a name="147545784"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545784" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545784">(Nov 12 2018 at 19:22)</a>:</h4>
<p>well we could make <code>ExClause</code> etc fully parametric, i.e. not using associated items :) but that would be a bit verbose</p>



<a name="147545788"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545788" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545788">(Nov 12 2018 at 19:22)</a>:</h4>
<p>right</p>



<a name="147545795"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545795" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545795">(Nov 12 2018 at 19:22)</a>:</h4>
<p>no perfect sol'n</p>



<a name="147545803"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545803" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545803">(Nov 12 2018 at 19:22)</a>:</h4>
<p>I think of the two I'd find an upcast a touch easier?</p>



<a name="147545805"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147545805" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147545805">(Nov 12 2018 at 19:22)</a>:</h4>
<p>ok so let's go for the explicit upcast</p>



<a name="147546162"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147546162" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147546162">(Nov 12 2018 at 19:28)</a>:</h4>
<p>Hi</p>



<a name="147546175"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147546175" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147546175">(Nov 12 2018 at 19:28)</a>:</h4>
<p>Good to hear of Chalk being so close to integration. :-)</p>



<a name="147549104"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147549104" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147549104">(Nov 12 2018 at 20:24)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> <span class="user-mention" data-user-id="131694">@scalexm</span> weird... mir emitting seems broken.</p>



<a name="147555190"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147555190" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147555190">(Nov 12 2018 at 22:25)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span> What's the status of <a href="https://github.com/rust-lang/rust/issues/44265" target="_blank" title="https://github.com/rust-lang/rust/issues/44265">https://github.com/rust-lang/rust/issues/44265</a> right now, do you know</p>



<a name="147555192"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147555192" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147555192">(Nov 12 2018 at 22:25)</a>:</h4>
<p>?</p>



<a name="147830681"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-11-12/near/147830681" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Gankra <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-11-12.html#147830681">(Nov 16 2018 at 17:10)</a>:</h4>
<p>is the performance impact of chalk being tracked anywhere?</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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